Filter for inverted pumps



Aug. 3, 1943. R. L. CHENAULT FILTER FOR INVERTED PUMPS Filed Dec. l0, 1942 INVENTOR. ROY L. @RENAULT a ATTORNEY y is valved to prevent return ilow to the well. 1 on upstroke, the well liquid is drawn into and Patented Aug. 3, 1943 FILTER Foa mvca'ran PUMPS Roy L. Chenault, akmont, Pa., assignor to Gulf Research & Development Company, Pittsburgh, Pa.; a corporation of Delaware Application December 1o, 1942, serial No. 468,583

` (ci. 10a-iso) Claims.

'I'his invention relates to a filter for inverted pumps which is effective to supply some of the `pumped liquid, freed from sandor other abrasive',

to the region of the pump packing to hush and lubricate the same, thereby to minimize erosion and deterioration of the packing and, 'consequently, to maintain the volumetric eiiiciency of the pump.

In pump:` of the inverted type a reciprocating barrel works upon a xed, hollow plunger which through the plunger for discharge past a valve in the barrel upon the following downstroke. in continued reciprocation of the barrel the liquid is pumped to the surface.'

Pumps of this type employ packing to seal the clearance space between the plunger and barrel, but where sand is carried along with the pumped liquid, as for example where sandy oil is encountered, the resulting abrasion and wear on the packing cause rapid deterioration. Replacement I is laborious and expensive as well as time-consuming.

These disadvantages are avoided in theusual reciprocating plunger type of pump by the provision of filtering ports through which some of the oil being pumped passes from the bore ofthe plunger into the clearance space yin the vicinity of the packing, the oil in the plunger being under tubing pressure. The application of a illter and sand scraping cup to the high pressure side of the. pump packing is complicated, in the case of an inverted pump, however, because the tubing pressure is not applied to the inner bore of the plunger, the oil being drawn therethrough, with the consequent tendency to draw sandy oil into the clearance space which communicates with the bore of the plunger. The condition Vwhich is sought to be avoided is thereby aggravated, ln,- stead. Filtering of the liquid supplied to the region 0f the packing must be accomplished under higher pressure than exists in the plunger.

'The present invention, therefore, has for its principal object the provision of a illter for inverted pumps wherein in both directions of reciprocation of the barrel filtered liquid is admitted to the clearance space around the packing to flush the same of abrasives which cause wear and deterioration. l v

A further object is to provide means for SuD- plying filtered liquid under pressure to the clear- Thus,

ance space of an inverted pump by by-passing Other and further objects and advantages of the invention will be manifest from the following description and drawing wherein:

Figure 1 is a view, partly in section, of an'inverted pump assembly incorporating the iilter arrangement of this invention.

Figure 2 is an enlarged vertical sectional view of the plunger.

Figure 3 is a transverse sectional view along line 3-3 of Figure 2. A

. Figure 4 is a vertical sectional view, taken taken J through the lower scraper ring and lter of a modified form of the invention.

Figure 5 is a transverse sectional View, along line 5-5 of Fig'ure 4.

Referring more particularly to the drawing:

A string of tubing I0 which extends into the well has a short reducing nipple II secured to its lower end by a threaded coupling sleeve I2. The upper'end I3 of the nipple supports a seating member I4' which carries friction cups or rings l5 in sealing contact with the wall of the nipple to" prevent leakage and to confine the flow of liquid from the well into the pump plunger I6 through a connecting pipe I1.

A pump barrel I8 Works upon the plunger and on downstroke discharges through an upwardly opening check valve I9 which is confined by a cage from which the sucker rod connection 20 extends. At its lower end the pump barrel mounts a sleeve 2 I which is formed with an inturned abut ment to retain the plunger within the barrel in installation of the pump and to bearupon the seating member I4 to secure the same inthe nipple I I in the n'al assembly, whereafter thev limit of the barrel stroke is determined by travel of the abutment between the lower end of the plunger and upper surface of the seating element I 4.

As shown more particularly in Figure 2, the plunger comprises a tubular body member whichw contains a ball check valve 22 resting upon seat 23 which is retainedbetween the threaded sections 24 and 25 of the plunger barrel. The sec.- tion 25 of the plunger is of reduced external diameter throughout a portion of its length and receives a plurality of pressure holding cups 26 with intervening spacers 2l, the packing assembly being held in position by a threaded retainer sleeve 28 which, additionally, clamps a sand scraper ring 29 spaced from the assembly ol packing rings by a sleeve 30. A similar but oppositely directed scraper ring 3l above the as- I sembly of packing rings is retained by the annular shoulder 32 formed on a tubular sleeve 33 scraper rings 3|.

plunger. plunger ows through the ducts 39, filter 4l and.

which lis secured to the plunger section 24. A

' plurality of ducts 34 in the sleeve 33 communicate space 40 to a series of longitudinally extending passages 4 I which are milled or otherwise formedy in the body oi the plunger part 25 and which,

plunger and barrel, sand scraping means above and below said packing, means forr delivering filteredI well liquid to the space between said sand scraping means and said packing, said meansl comprising a duct communicating with the space exterior to the plunger on opposite sides of said lower sand scraper, a lter in said duct, a duct communicate with a space above the lower scraper ring in which a cylindrical lter 4I is retained by woven wire screens 42. Ducts 43 lead fromsuch space to the exterior of the plunger between the lower backing rings and the lower scraper, ring v29. A

In the modied form o'f invention shown in Figure 4 the passages 44 are shown as formed in the surrounding sleeve 41 rather than in the plunger body. In both forms of the invention,

however, the liquidA to be filtered and discharged into the clearance space flows through passages which'by-pass the lower sand scraper, the latter ,being at the high pressure side of the packing. The passages terminate above and below the 1 scraper cup and, have no communication with the bore of the plunger as a consequence of which liquid forced through them is under higher pressure than that existing within the plunger.

On upstroke of the pump valve liquid is drawn from the well through the seating element I4 and pipe llpast check valve 22 in the Iixed At the same time liquid around the communicating ducts 43 into the clearance space inthe region ofthe packing 26. `.This liquid being filteredv contains no abrasive which `will cause 'i Aerosion of the packing and its subsequent rapid deterioration.

On the succeeding downstroke of the pump barrel the upper scraper ring is expanded to'contact with the barrel and since the check valve 22 is closed, pressure within the plunger causes liquid above the valve to pass outwardly through the ducts 38 and lter 36 to be discharged through orifice 35 .into the space below the Yupper sand scraper, thereby inturn 'to discharge sand-.free liquid into the clearance in which the packing rings 26 operate. Thus, it will be' apparent that a part of the oil or other4 liquid supplied tothe pump is filtered and discharged to the space between the plunger and barrel in region of the packing rings in both directions of reciprocation, such ltered liquid serving to flush the space and lubricate the'packing rings, and to equalize pressure across the scraper rings. As a consequence erosion and wear are minimized and high volumetric eiciency of the pump is maintained without requiring frequent replacements ofparts which would otherwise be subjected 'to abrasion.

What I claim is:

1. In an inverted deep well pump, a valved plunger anda barrel reciprocable thereon, packing in the clearance space between said plunger and barrel, sand scraper means in advance of said packing, a duct opening into the clearance space above and below said sand scraper means, and a filter in said duct. l

2. In an inverted deep well pump, a valved plunger and a coacting reciprocating barrel, packing in the clearance space between said for delivering well liquid under pressure to the space exterior to the plunger below the said upper sand scraper, and a lter in said last'named duct.

y3. In an inverted deep well pump, a xed, tubular plunger 'and a coacting, reciprocating barrel, a valve in said plunger to prevent return flow of liquid, packing means carried by said plunger to provide a seal against the wall of said barrel,

la lower sand scraper carried by said plunger, a

l passage circumduetingsaid lower sand scraper and terminating exteriorly of said plunger, filter means in said passage, a'secondsand scraper car'- ried by said plunger at a point abovev the said valve therein, a passageway providing communication between the exterior and the bore of said r plunger, and a lter in said passageway, wherebyupon upstroke of said barrel liquid under pressure is` discharged through said first lter into the clearance space between the upper and lower sand Scrapers, and upon downstrokeliquid under pressure above said plunger valve is discharged from the plunger bore, through said second lter,

and also into the clearance space `in the region of the packing.

4. In an inverted deep well pump, a xed tubular plunger and a barrel reciprocable with respect thereto, the barrel and plunger being mountedl in a tube string through which liquid is admitted from the well to the interior of the plunger, packing carried by the plunger and sealing the clearance space between it and the barrel, check valves in said plunger and barrel opened successively in reciprocation of the barrel for lifting well liquid through the plunger and discharging it into the tube string, sand scraper means carried by said plunger above and below the packing, a passageway circumducting the lower sand scraper and terminating at the exterior of the plunger for admitting well liquid from below the lower sand scraper under pressure in `downward reciprocaabove said lower sand scraper, a lter in said passageway to remove abrasive from the liquid so delivered to the region of the packing, a passageway below the upper said sand scraper communicating with the interior of said, plunger above the valve therein, and a filter in said passageway to remove abrasivefrom the liquid delivered under pressure within said plunger in upstroke of the barrel, thereby on successive strokes of the barrel to discharge ltered liquid to the clearance space in the region of the packing for ushing the same.

5. In an inverted deep well' pump, a valved plunger and a barrel reciprocable thereon, packing in the clearance space between said plunger and barrel, scraping means spaced from said packing, a, duct for conveying liquid to the clearance space in the region between the sc raping means and packing, from the clearance space on the opposite side of said scraping means, and a filter for removing abrasive particles from liquid delivered to the region between said scraping means and packing. f

- ROY L. CHENAULT. 

